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Date:      Wed, 11 Dec 2019 10:19:05 -0700
From:      Scott Long <scottl@samsco.org>
To:        Alan Somers <asomers@freebsd.org>
Cc:        Steven Hartland <steven.hartland@multiplay.co.uk>, src-committers <src-committers@freebsd.org>, svn-src-all <svn-src-all@freebsd.org>, svn-src-head <svn-src-head@freebsd.org>
Subject:   Re: svn commit: r355430 - head/sys/cam/scsi
Message-ID:  <820BE55B-AE32-44E7-8AC7-245EF6F86F8B@samsco.org>
In-Reply-To: <CAOtMX2iySx2sn2q9qm2FBudpAEBZX6UkaCR3P%2B%2BDGBjntUG=Zg@mail.gmail.com>
References:  <201912060006.xB6066qR058963@repo.freebsd.org> <CAHEMsqaO7SrMQyXVzUdNSvDBTxFwD95s5i2dK=h5an-xvrdcgA@mail.gmail.com> <CAOtMX2iySx2sn2q9qm2FBudpAEBZX6UkaCR3P%2B%2BDGBjntUG=Zg@mail.gmail.com>

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U+FFFD doesn=E2=80=99t make sense for an ASCII string, but 0x3F might.  =
Any idea what Windows shows for this device?

Scott

> On Dec 11, 2019, at 8:42 AM, Alan Somers <asomers@freebsd.org> wrote:
>=20
> In this case the offending descriptor is solid 0xFF, so replacing =
individual characters wouldn't accomplish anything.  I can imagine a =
different buggy expander that has just one or two bad characters.  In =
that case, it would make sense to replace them.  But replace them with =
what?  The UTF replacement character 0xFFFD isn't an option, because the =
result is supposed to be ASCII.  There's no other obvious choice, which =
is why I chose to replace the whole thing.
> -Alan
>=20
> On Fri, Dec 6, 2019 at 2:40 AM Steven Hartland =
<steven.hartland@multiplay.co.uk> wrote:
> If the illegal chars where removed or replaced would the result be =
useful, if so might that be a better approach?
>=20
> On Fri, 6 Dec 2019 at 00:06, Alan Somers <asomers@freebsd.org> wrote:
> Author: asomers
> Date: Fri Dec  6 00:06:05 2019
> New Revision: 355430
> URL: https://svnweb.freebsd.org/changeset/base/355430
>=20
> Log:
>   ses: sanitize illegal strings in SES element descriptors
>=20
>   The SES4r3 standard requires that element descriptors may only =
contain ASCII
>   characters in the range 0x20 to 0x7e.  Some SuperMicro expanders =
violate
>   that rule.  This patch adds a sanity check to ses(4).  Descriptors =
in
>   violation will be replaced by "<invalid>".
>=20
>   This patch fixes "sesutil --libxo xml" on such systems.  Previously =
it would
>   generate non-well-formed XML output.
>=20
>   PR:           241929
>   Reviewed by:  allanjude
>   MFC after:    2 weeks
>   Sponsored by: Axcient
>=20
> Modified:
>   head/sys/cam/scsi/scsi_enc_ses.c
>=20
> Modified: head/sys/cam/scsi/scsi_enc_ses.c
> =
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D
> --- head/sys/cam/scsi/scsi_enc_ses.c    Thu Dec  5 19:39:51 2019       =
 (r355429)
> +++ head/sys/cam/scsi/scsi_enc_ses.c    Fri Dec  6 00:06:05 2019       =
 (r355430)
> @@ -110,7 +110,7 @@ typedef struct ses_addl_status {
>  typedef struct ses_element {
>         uint8_t eip;                    /* eip bit is set */
>         uint16_t descr_len;             /* length of the descriptor */
> -       char *descr;                    /* descriptor for this object =
*/
> +       const char *descr;              /* descriptor for this object =
*/
>         struct ses_addl_status addl;    /* additional status info */
>  } ses_element_t;
>=20
> @@ -1977,6 +1977,35 @@ ses_publish_cache(enc_softc_t *enc, struct =
enc_fsm_sta
>         return (0);
>  }
>=20
> +/*
> + * \brief Sanitize an element descriptor
> + *
> + * The SES4r3 standard, sections 3.1.2 and 6.1.10, specifies that =
element
> + * descriptors may only contain ASCII characters in the range 0x20 to =
0x7e.
> + * But some vendors violate that rule.  Ensure that we only expose =
compliant
> + * descriptors to userland.
> + *
> + * \param desc         SES element descriptor as reported by the =
hardware
> + * \param len          Length of desc in bytes, not necessarily =
including
> + *                     trailing NUL.  It will be modified if desc is =
invalid.
> + */
> +static const char*
> +ses_sanitize_elm_desc(const char *desc, uint16_t *len)
> +{
> +       const char *invalid =3D "<invalid>";
> +       int i;
> +
> +       for (i =3D 0; i < *len; i++) {
> +               if (desc[i] < 0x20 || desc[i] > 0x7e) {
> +                       *len =3D strlen(invalid);
> +                       return (invalid);
> +               } else if (desc[i] =3D=3D 0) {
> +                       break;
> +               }
> +       }
> +       return (desc);
> +}
> +
>  /**
>   * \brief Parse the descriptors for each object.
>   *
> @@ -2061,7 +2090,8 @@ ses_process_elm_descs(enc_softc_t *enc, struct =
enc_fsm
>                 if (length > 0) {
>                         elmpriv =3D element->elm_private;
>                         elmpriv->descr_len =3D length;
> -                       elmpriv->descr =3D &buf[offset];
> +                       elmpriv->descr =3D =
ses_sanitize_elm_desc(&buf[offset],
> +                           &elmpriv->descr_len);
>                 }
>=20
>                 /* skip over the descriptor itself */




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